Wednesday, December 31, 2008

Kodak filed an application US20080315272 on control of 4T pixel floating diffusion capacitance in such a way that it's low for small signals and large for large signals. The pixel schematics is shown below:

Transistor 201 opens only for large signals, increasing floating diffusion capacitance to accomodate the larger charge.

Omnivision's application US20080318358 talks about using indium doping for the photodiode pinning layer. Indium allows for a shallower implant layer with higher concentration than commonly used boron. An indium-boron combination is also applied for the patent.

Tuesday, December 30, 2008

2009 IS&T/SPIE Electronic Imaging Science and Technology Symposium will be held on January 18-22 in San Jose. The conference has a full track on image sensors and related areas. Below are just few of the most interesting papers to be presented on the Symposium:

Bart Dierickx from Caeleste presented his 3D sensor ideas on IEEE Nuclear Scinece Symposium in Dresden, Germany, Sep. 2008. The presentation talks about the new design approaches in 3D world. One might give up pinned photodiode and 4T CDS scheme and needs to look for other ways to suppress kTC noise.

Bart presents an idea how this can be accomplished without resorting to active reset schemes. I'm unable to understand how come that the proposed reset reduces kTC noise, but the eldo transient noise simulation in the inset seems to confirm this:

Sunday, December 28, 2008

While we are at testing, Gamma Scientific offers calibrated digital light sources for image sensor testing in its Eigenlite RS-5 series. The sources can be used for photometric and radiometric calibrations and sensor's linearity tests.

Saturday, December 27, 2008

It came to my attention that Korea's HVS - HyVision System offers a full range of solutions for testing image sensors and camera modules, starting from simple PC add-on boards all the way to the automatic module production testers.

Wednesday, December 24, 2008

Digitimes: TSMC has received few orders from OmniVision in December, which is a sign of the client's pessimistic outlook for the handset market in the first quarter of 2009, according to Digitimes sources.

Yahoo: Micron reports relatively stable image sensor quarterly sales compared to the preceding quarter. The company’s gross margin on sales of Imaging products also remained stable compared to the previous quarter, reflecting a slight decrease in costs per part.

Seeking Alpha Micron's Earnings Call transcript has just one mention about imaging business:

Hans Mosesmann – Raymond James analyst:

On the sensor business it was flat and that’s unusually strong too in this environment, are you gaining share or is it that you’re not exposed to some of the markets where perhaps they’re seeing a lot more weakness then you saw.

Steven Appleton, CEO:

I think we did gain some share in the quarter but if you looked at some of the other forecasts and the competition, I think that’s indicative of what we’ll probably experience too. In other words I don’t think we’re going to escape the general economic decline and we would expect, and by the way its also the season of course is weaker, so we would expect for the what we call our Q2 or the calendar Q1 to be inline with what others are forecasting and it’ll be down for the quarter.

Intertech-Pira Image Sensors Europe 2009 conference published a provisional program. The conference is to be held on March 24-26, 2009 in London, UK. The program has quite a few interesting presentations:

Saturday, December 20, 2008

EETimes: After many months of negotiations Panasonic acquired Sanyo for $9B. At some point Sanyo was the biggest CCD manufacturer for camera phones, but it was unable to switch over to CMOS sensors and lost its market share. Still, Sanyo produces a number of CCDs till now and has CCD-dedicated fab. The acquisition should strengthen Panasonic image sensor group.

In a separate move Panasonic will absorb its wholly owned subsidiary Panasonic Semiconductor Device Solutions Co. Ltd. (PSCDS). PSCDS used to be responsible for the camera module business. The move is expected to take effect on April 1, 2009.

Thursday, December 18, 2008

Tech-On published yet another report on IEDM presentation of Cu-In-Ga-Se image sensor by Rohm and AIST. The sensor has a layer structure composed of n-type ZnO, i-type ZnO, CdS, CIGS and Mo, which are arranged in this order from the top surface. The sensor is placed on a Si LSI via the molybdenum (Mo) layer serving as an electrode. The ZnO layer was formed using RF sputtering. The sensor works in avalanche multiplication mode.

Venture Beat: Despite the investment freeze talk, Pixim raises $13M from Mayfield Fund, Ridgewood Capital and Tallwood Venture Capital. The company will use the money to accelerate its expansion in overseas markets, fuel new product development, and expand its marketing and sales programs. China is about 15% of its business, but Korea and Taiwan are also big markets, as are the U.S. and Europe.

Customers include the biggest makers of security cameras: GE Security, Honeywell, JVC, Pelco, Dallmeier, and Siemens. Pixim has now raised $106.7M, including the latest round.

There is only one image sensor in EDN's list of "The Hot 100 Electronic Products of 2008" and it's Kodak KAI-02150 CCD. What makes this 2/3" CCD different is its ability to provide 1080p HD video at 60fps speed. Congratulations, Kodak!

Yahoo: Dalsa presents its new 48MP 6um-pixel CCD for professional photography in a presentation at IEDM. Eric-Jan Manoury, a scientist at DALSA's Eindhoven R&D lab, gave the presentation titled "A 36x48mm2 48M-pixel CCD imager for professional DSC applications," highlighting the advances it delivers in increased QE, lower noise, and higher DR compared to previous generation or competitor devices.

This is claimed to be the first large image format imager with high pixel rate of 100 MHz, 74 dB of DR and 55000e of full well capacity. The IEDM article is published on Dalsa site.

Wednesday, December 17, 2008

Solid State Technology published Chipworks analyst Dick James' report from IEDM'08. Here is what Dick says about image sensors:

"Chipworks has been focusing on image sensors for a while now, so Rohm's announcement of a CIGS on CMOS sensor (paper 11.2) caught my attention. CIGS (copper indium gallium selenide) is one of the hot materials in the PV field, so the idea of using it for an image sensor is not that far off the wall -- the big problem has been high dark current.

Rohm gets around this by using a double layer of zinc oxide as the top blanket electrode. One layer is semi-insulating ZnO, and the top sub-layer is Al-doped to give conductivity; this has the dual advantage of isolating the pixels and reducing dark current. The CIGS is co-evaporated on to a molybdenum base layer/back contact (which contacts the top metal layer of the CMOS scanning chip below), with a CdS buffer layer under the ZnO bi-layer.

The pixels are 10μm × 10μm in a 352 × 288 array, so this is clearly a proof of concept. The sensitivity can be extended to sub-lux illumination levels by biasing the photodiode to induce avalanche multiplication. Since the photodiodes are on top of the die, they have an aperture ratio close to 100%, and this coupled with the CIGS spectral response extending into the near-infra-red makes the sensor suitable for automotive and security applications.

In the same session Samsung compared 1.4μm frontside- and backside-illuminated (BSI) sensors (paper 11.4).....Samsung claims that the technology will extend pixel size down to ~1μm."

Tuesday, December 16, 2008

Earth Times: Due to the current economic slowdown, Toshiba plans to stop production for short periods at some of its fabs. One of the facilities affected is Oita operations, responsible for image sensors and SoC LSI production. The 300mm wafer lines will stop on January 5 and 6 for maintenance and other lines will stop for 22 days from December 24 to January 14.

My understanding is that Toshiba image sensors are manufactured on 200mm lines (am I right?), meaning they are to shut down for 22 days.

Monday, December 15, 2008

Yahoo: OmniBSI has been selected by Electronic Design Magazine as the 2008 'Best Image Sensor Technology'. The publication's annual 'Best Electronic Design' awards are based on editor's choice of the most significant designs and innovations introduced throughout the year. OmniVision's BSI technology was selected for its revolutionary approach to digital imaging.

Saturday, December 13, 2008

Magnachip's application US20080296630 talks about applying negative bias voltage to transfer gate transistor during the integration. It looks like today everybody uses negative bias to reduce dark current. One possible problem here is increase in blooming and everybody solves it in its own way. Magnachip proposes a special burried channel for blooming current. This complicates the doping scheme of the transfer gate area, so I doubt that this idea finds a big use.

Nokia camera team filed application US20080297816 on improved black level correction. They try to compensate black level gradients across the sensor array by measuring black level in many points on the periphery of the array and interpolating the results for all the pixels, doing it separately for each color. There is nothing unusual in the idea itself, other than it points out that the black level spatial variations is probably the real problem in the sensors that Nokia uses.

Thursday, December 11, 2008

Advasense put its Intertech-Pira Image Sensors 2008 Conference presentation on-line (the first one in the list here).

The main statement in the presentation is that modern small pixel sensors are not good in capturing image: in good light there is no enough full well capacity, while in low light there is no enough photons. So, the company proposes its large full well photodiode as a solution for daylight, while an on-sensor embedded image stabilization is supposed to increase signal at low light.

Wednesday, December 10, 2008

Chipworks did a first round of analysis on Omnivision split pixel sensor back in April and kindly agreed to shed some light on the subject even though they haven't gone forward with a full analysis. Chipworks has posted a flyer based on the brief analysis, a custom landing page can be found here. (This page is temporary, so keep the pdf file, if you need it.)

The design is quite interesting. Each pixel has two photodiodes per each 6um pixel, as depicted below:

Each split pixel has dual microlens above, one per each photodiode (I think Visera spent many sleepless nights to optimize these oval lens shapes):

It looks to me that Omnivision used dual exposure technique to achieve its goal of 110db DR with this sensor. Two interleaved rolling shutters can run across the array, where reset curtain is followed by two read curtains - short and long one. Then the two readouts are combined into a single HDR image. Obviously, there should a large memory to hold the intermediate frame results. The die photograph in Chipworks document supports this guess, showing a huge memory-dominated digital portion.

So, to me this looks like a dual exposure sensor with on-chip HDR reconstruction. Its main competition are Pixim digital pixel and Toshiba-like dual exposure pixels with charge skimming.

In principle Pixim can get better dynamic range, but I believe Omnivision 4T pixel is better in low light, especially if two photodiodes operate in normal mode, with same exposure on the two photodiodes.

Comparing it with Toshiba solution, I'm less sure about Omnivision advantages. Toshiba sensor might have some linearity artifacts when connecting short and long exposure ranges. Omnivision probably does not have this. However, Toshiba has an advantage in low-light sensitivity in HDR mode because Omnivision sensor effectively loses half of the light for the short exposured photodiode.

One question that bothers me though, is that the two photodiodes are spacially shifted relative each other. So, there might be some color artifacts when interpolating the edges on HDR picture. It's probably not something fundamental, but might take some effort to correct.

Tuesday, December 09, 2008

Yahoo: Robert W. Baird & Co. analyst Tristan Gerra told investors in Dec. 3 note that competition from "ultra-low-cost" rivals based in Asia is driving the company's revenue decline. Gerra added that OmniVision is likely to lose more market share next year as more mobile phone makers switch to higher-resolution sensors -- a market in which the company is not as well-positioned as competitors.

So, it looks like Gerra does not count on Omnivision's BSI and EDoF success, which, in theory, could propel the company to the market leader position in high-res products. I wonder why he is that skeptical?

EETimes: United Business Media Ltd., the publisher of EE Times, has acquired for at least $8M Sanguine Microelectronics, a semiconductor reverse engineering company based in Shanghai. UBM will merge Sanguine into its existing Semiconductor Insights (SI) group in Ottawa that provides chip and patent analysis services. The deal also includes possible payments of up to $9.5M to the Shanghai company over three years if the company meets unspecified business targets.

The deal nearly double's SI's headcount and expands its lab capabilities. Sanguine employs about 130 people with a lab in Shanghai and an office in France and has annual revenues of about $4 million. SI has about 160 employees with labs in Ottawa and Warsaw and sales offices in Japan, Korea, Singapore, Taiwan, China, Europe and Israel.

Both companies published a lot of reverse engineering reports on image sensors, albeit their recent focus seems to shift elsewhere.

It was brought to my attention that Omnivision's PR from a week ago mentions so-called "split pixel":

"The OmniVision OV10620 HDR sensor incorporates a unique split pixel design that operates using different exposure times to allow one part of the pixel to capture dark tones within an image, and the other part to capture bright tones. The two images are then merged using proprietary signal processing technology ensuring the visibility of entire scenes in high-contrast environments. The OV10620 is capable of performing at a dynamic range of up to 110dB in either color or black and white."

Anybody can shed some light on this pixel work? Any published patents on it?

EETimes: Sony plans to slash about 8,000 jobs in its electronics business, or about 5 percent of its work force in the sector. The cutbacks involve its CMOS image sensor and other product areas. As part of the plan, Sony intends to cut IC investment expenditures this fiscal year by outsourcing a portion of its planned increase in the manufacturing of CMOS image sensors for use in mobile phones.

Yahoo: Aptina announced that it shipped one billion image sensors since it began manufacturing image sensors in 2002. Of the one billion sensors shipped, approximately 55 percent were megapixel or greater. Aptina maintains a product portfolio of over 70 CMOS image sensors.

Monday, December 08, 2008

Yole's site I-Micronews published an interview with Youssef Benmokhtar, Marketing & Business Development Director on Nemotek, the first licensee of the full portfolio (SHELLCASE and OptiML) from Tessera.

The company was established in September 2007 as a subsidiary of MEDZ (a Moroccan company with more than 1.2B$ of assets) as a Government initiative to position Morocco as a key player within the microelectronics industry and new sciences arena. Nemotek is claimed to be the only company in the world to date to offer a one-stop-shop approach for wafer-level cameras.

Saturday, December 06, 2008

I always enjoy reading Siliconfile patents. It looks to me that the company has quite a few unusual, sometimes bright, ideas. The newly ublished application US20080290440 proposes to reduce the light reflection from silicon by using "concavo-convex surface" shaped surface. The picture below shows how exactly this reduces the reflection:

I'm not sure if this idea works for small pixels, where pixel size is of close to wavelength. Also, I believe the process of creating such a surface is not simple. But I like fresh, out of the box thinking of Siliconfile engineers.

Application US20080291309 by University of Pennsylvania in Philadelphia talks about pixel with amplifier transistor, instead of source follower. The application is written in a scientific paper style, with good comparison of different techniques and their strong and weak points. While I don't like their idea and especially their proposed implementation, it's a good educational read.

Friday, December 05, 2008

Chipworks got a hold of a Sony 1.4um 8MP IMX046 sensor in a commercially available product (probably from LG or Sony-Ericsson phone). The formal report announcement is prepared for next week. The die picture below reveals very compact sensor design. I hold my breath to see the full report available.

Yahoo: Samsung announced that it has expanded its portfolio of CMOS image sensors to include a new high-definition 1/4-inch, 1.2MP SoC imager, the S5K4AW, for notebook and desktop computers. Instead of more usual 1.3MP, 1.2MP is better suited for HD video applications. By binning in 2x2 pixel groups, the S5K4AW’s 1.2Mp resolution (1280x960 pixel format) also can display standard VGA format without annoying problem of losing the top or the bottom of a scene while video conferencing or video file sharing on social media networks such as YouTube.

The binning technique used by Samsung’s new S5K4AW sensor for VGA resolution also significantly improves the imager’s sensitivity to low light. Samsung claims that the industry’s typical method of binning results in an improved sensitivity of approximately 1.2x - I'm not sure how they got this number. Samsung’s 2x2 binning shows a sensitivity improvement of nearly 3x. This is critical when the only illumination on the scene might be from the computer screen itself.

The new S5K4AW imager is a 1/4-inch sensor that uses a 2.8um pixels. It supports 720p HD video at 30fps and VGA video at up to 60fps.

Samsung is currently sampling S5K4AW sensor to select customers. Mass production is expected in the first half of 2009.

Wednesday, December 03, 2008

Seeking Alpha publishes a transcript of Omnivision Q2 FY2009 Earnings Call. As many have expected, the guidance for the next quarter is down and the company forecasts an operating loss. Its strong cash position of $283M should help it survive and continue to invest in new technologies during the downturn, at least Shaw Hong, the CEO, believes so. He also tells that the company has already taken steps to reduce its operating expenses.

Gross margin for the Q2 was 25% compared to 25.2% the previous quarter. Excluding stock-based compensation expense gross margin was 25.4% compared to 25.7% reported in the Q1.

Omnivision continues its work to migrate to 300-millimeter wafer production, both with TSMC and VisEra.

Ray Cisneros, VP of Sales, says:

During our fiscal second quarter, we sold about 99 million units into the marketplace.....Our 2-megapixel sensor shipments into smart phones have been particularly strong over the past two quarters. And now, this quarter, we have ramped up our 3-megapixel sensor shipments.....just over 60% of our revenues came from the mobile phones and just under 40% from emerging products. As for the unit mix in the quarter, the VGA and below was 65%, 1.3-megapixel was just over 15%, and 2-megapixel and above was just below 20%.....sensors on notebooks represented our strongest growth area during the quarter and represented approximately 30% of the company’s revenue.

One of suspicious omissions in the conference call was absence of any word on BSI sensor volume production start, general sampling or design wins. No analyst asks about it in Q&A session either. This brings some food for thought.

Correction: As written in comments, the earnings call does have a statement that two BSI products will be qualified for mass production in the first half of 2009.

Monday, December 01, 2008

Altasens presents its new idea on tapered reset usage in 4T pixel on Intertech-Pira Image Sensors 2008 Conference. The pixel has 2 modes of operation. At large signal it works like any other 4T pixel. In low light mode the pixel transistor works in common source mode where the photodiode charge is transferred to its Miller capacitance. This way pixel has a higher gain, so that the column circuitry noise is less important. The slide below shows the idea:

Sony presented a picture from its new 8MP 1.4um pixel sensor on Intertech-Pira Image Sensors 2008 Conference. The picture is given below, as appeared in Sony .pdf file. Essentially, this is a copy of the picture from the official Sony PR, but with higher resolution and illumination conditions reported. The picture is quite good for a first generation sensor (click on it to expand):

Sunday, November 30, 2008

Yahoo: Two new DALSA High Quanta sensors with resolutions of 1044 x 1044 (IA-DJ-01044-00-R) and 524 x 524 (IA-DJ-00524-00-R) feature the same 24 um size pixel. The new sensors are said to employ the latest designs in output amplifiers providing low noise at high data rates.

The sensors are available now and will be showcased this week at the Radiological Society of North America (RSNA) Show. For applications demanding UV sensitivity and > 90% QE, back side thinned (BST) devices will be available on a custom basis. The standard front side illuminated product's QE is said to be peaking at more than 70%.

Saturday, November 29, 2008

The whole family is targeted to camera phone applications. 3MP IMX029 and IMX058 differ by the interface type: IMX029 has serial interface while IMX058 has parallel one. 5MP IMX034 and 8MP IMX043 have conflicting data on their interface: the header claims they use parallel one, while later in the text both are mentioned as having serial sub-LVDS interfaces. 8MP IMX043 is able to operate at 15fps speed at full resolution.

The sensors use 0.14um 1P4M Cu process, which allowed for an increase in chief ray angle, as compared with the 2.5um ancestor pixel.

Friday, November 28, 2008

Magnachip applications US20080283885 and US20080283886 talk about saving a reset transistor in 4T pixel by substituting it by a diode built vertically above the substrate. 20080283886 pixel also uses JFET as a source follower transistor to reduce the noise, while 20080283885 pixel has a set diode, in addition to the reset one. The reset and set diodes are formed between the diffusion and poly, amorphous silicon, local epi-layer or metal (Schottky version). Probably, JFET was thrown in 20080283886 to improve its chances to be granted, as when each idea separately would be rejected (there is a good chance they would), it still might pass as a combination.

The set diode in 20080283885 application improves the reset operation of the reset diode by biasing both at slightly different voltage, so that a small forward current flows through the diodes, keeping floating diffusion at mid potential.

Sony application US20080284250 talks about 3-level power supply for powering transfer get of 4T pixel. 3 levels are used to reduce image lag and noise, but it creates a number of start-up problems in mobile device, where the highest voltage might be not available initially. Sony proposes a solution for this specific problem.

Sharp application US20080284891 describes about yet another circuit eliminating "black sun" effect. For those who is still suffering from it, it's worth reading.

Thursday, November 27, 2008

ISSCC 2009 program just has been published (even though the page is still empty, clicking on "Press" drop down menu and choosing "Advanced Program" works). This year one of the pre-conference forums is devoted to Medical Image Sensors, quite interesting stuff.

There are many interesting ideas to be presented on the Imagers session. The most interesting to me is Toshiba 8MP sensor.

A 1/2.5-inch 8Mpixel CMOS Image Sensor with a Staggered Shared-Pixel Architecture and an FD-Boost Operation

A 1/2.5-inch 8Mpixel CMOS image sensor employs a staggered shared-pixel architecture to suppress Gr/Gb sensitivity imbalance. It also employs an FD-boost operation using the Cgs and Cgd of amplifier transistors to yield large FD capability and low dark random noise. It achieves a Gr/Gb sensitivity ratio of 99.7%, random noise of 2.6erms and a pixel capacity of 7.7ke-.

Now, when Toshiba says it, FD boost idea seems quite natural one to use. I have not heard anybody used it though.

A CIF-format charge-multiplication 0.35μm 2P4M CMOS image sensor with 10μm pixel pitch is presented. It can execute charge multiplication using impact ionization of photo-generated signals within each pixel. For a significant increase in SNR at low light levels, up to 60× charge multiplication is achieved at a readout speed of 100μs/frame.

Once we are at video applications, Aptina presents its high DR VGA sensor with very impressive spec:

A Dual-Conversion-Gain Video Sensor with Dewarping and Overlay on a Single Chip

A. R. Huggett, C. Silsby, S. Cami, J. BeckAptina Imaging

A 47mm2 video sensor SoC comprises a 60fps 640×480 array of dual-conversion-gain 5.6μm pixels with >80dB DR, noise floor of <1erms and switchable sensitivities of 2.5V/lx·s or 11.9V/lx·sand corresponding PRNUs of 0.57% or 0.68%, a video processor for correcting optical warp of up to 96 lines together with perspective adjustment, and a video overlay circuit.

A CIS with 13b column-parallel cyclic ADCs is presented. A single-ended architecture with low read noise increases DR up to 71dB. A vertical FPN of 0.1erms is attained using digital CDS, which performs A/D conversion twice in a horizontal scan period of 6.83μs. The imager has 7.07V/lx·s sensitivity, 5.6μm ADC pitch, 61μV/e- conversion gain, 4.7erms read noise and <0.5 LSB DNL

I was expecting more papers on consumer low-cost BSI sensors and small pixels, but this year ISSCC seems to omit these themes - quite strange, considering the huge efforts that industry is spending on this stuff.

Tuesday, November 25, 2008

Fairchild Imaging presented a 4T pixel paper on SPIE Astronomical Telescopes and Instrumentation Conference, 23-28 June 2008, Marseille, France. It shows quite a conventional 6.5um pixel made in 0.18um process. What really sets it apart is a very low full well - only 1.5Ke at most.Update: As mentioned in comments, probably the full well is limited by column amplifier in high-gain mode. The pixel's native full well is probably higher, albeit the paper does not give an explicit number.Update #2: Two sentences removed, as said in comments.

Yahoo: Sony is rumored to sell low resolution CCDs for medical applications for hundreds of dollars each. Many other companies dream to penetrate to this market too.

Omnivision announces its second generation medical sensor. The OV6930 square sensor has a resolution of 400 x 400. The new sensor is based on 3um 4T pixels, has optical format of 1/10 inch and a packaged footprint of 1.8 mm x 1.8 mm. The sensor's size and high low-light performance enable its use in a broad scope of medical endoscopy applications including colonoscopy, gastroscopy, OB/GYN, urology and bronchoscopy.

OV6930 uses a new, patent pending serial I/O, which allows for two-wire cabling up to 14 feet and contributes to its very low power consumption of 80mW with and 10mW without IO usage. It's capable of operating at 30 fps in full 400 x 400 resolution, and 60 fps at 400 x 200 resolution. The pixel sensitivity is said to be 3300 mV/Lux-second.

Wednesday, November 19, 2008

Yahoo: Aptina announced MT9P013 5MP 1/3.2-inch image sensor based on improved 1.75um pixels. The new sensor leverages the same technology Aptina is integrating into its 1.4um image sensors. Specifically, MT9P013 sensor implements the light-gathering advancements from Aptina’s 1.4um pixel sensors. The new sensor’s low-light sensitivity improvement is 2X over the MT9P012 for binning modes.

The sensor supports 720p HD video at 60fps and full 5MP resolution at 15fps. The sensor includes 2-lane MIPI, CCP2 and Parallel interfaces.

MT9P013 samples are presently available with mass production scheduled for the end of January 2009.

Tuesday, November 18, 2008

Yahoo: One clear beneficiary of Magnachip exit from image sensor business is Pixelplus. MagnaChip has completely withdrawn its appeal on the disputed process patents in Seoul High Court. Given this, the previous lower court decision that Pixelplus did not infringe any of the disputed process patents asserted by MagnaChip has become final and conclusive, and MagnaChip's patent infringement claims on the process patents will no longer be contested or remain at issue.

Honestly, I've never understood the business justification of Magnachip's lawsuit. Pixelplus is a very minor player on the image sensor market. Even if convicted, it would pay an insignificant sum for the Magnachip's bottom line. To me this dispute seemed like settling some personal scores between people in the companies. After all, both Magnachip and Pixelplus people worked together at Hyundai Semiconductor and LG Semiconductor. May be some of them think that their ideas were stolen and look for punishment.

At first I liked the idea, but after a brief look on the web side, the proposed metrics look to me partially wrong and partially unnecessary complicated.

I can understand the rationale behind Nokia SNR10 figure to measure sensor's low-light performance. It represents the minimum illumination to achieve SNR10 after color correction matrix (CCM) bringing sensor's colors to the standard set. Being incomplete as it is, SNR10 figure is simple to use and compare. Talking about DSLR sensors, I would complement it by SNR100 or SNR200, for example, showing the minimum illumination to get near perfect picture with standard colors. Such a simple figure is full of omissions, but it's very synthetic it terms it combines a lot of sensor parameters in a single, simple to use number.

Back to DxO approach, there is no such a good synthetic number as SNR10. It's more complex as there are few different numbers making it harder to compare. For example, what if "color depth" figure is excellent, but colors are wrong and suffer from metamerism? Talking about DR and ISO measurements, how do they compare visibility of different noises? One sensor might be dominated by nicely scattered Gaussian noise, other might have mostly row or column noise, yet another one might suffer from "salt and pepper" noise. All these noises have very different visibility.

Not that Nokia SNR10 has less problems, but at least it's much simpler and much more synthetic. So if I would propose DSLR sensor metric, I would go for SNR100 measured according to Nokia procedures.

What I liked though is the database with quite a detailed measured data. The pure measured data is really valuable. Kudos to DxO for making this openly available!

“Their [sensors] pricing was in significant decline last year, so not much was expected to happen there. But then Toshiba (Tokyo) not only announced that they would be the first to put through-silicon vias (TSVs) into their CMOS image sensor to reduce the size, but that they were selling it essentially at the same price. This forced the other players to jump on the bandwagon over the next 12 months. So Samsung (Seoul, South Korea), Micron, Oki (Tokyo) — all the big players in CMOS image sensors — followed suit at a time when the price was significantly deteriorated. They did this only because Toshiba made the first move, and they had no choice but to follow.”

"Although inventory levels generally tend to serve as a moderating factor to the purchase of new devices, in the case of the new CMOS image sensor the OEMs that did not have it found that they were stuck with their inventories of non 3-D devices. Meanwhile, those who were able to acquire and use them made a considerable profit based on the architecture’s smaller form factor."

Sunday, November 16, 2008

I spotted just two noteworthy applications in the last two weeks flow of more than 40 image sensor-related applications:

Micron application US20080265295 talks about making a deep red pixel in Bayer pattern, while green and blue pixels are shallower. This might be a useful idea for old simple 3T pixels, but Micron is going to apply it to 4T design. The problem with it is that essentially Micron has to optimize two different pixels in the same sensor, including dark current, image lag, full well, etc. All these are long and hard optimizations, requiring many trade-offs. Having two different pixels to optimize certainly does not help in this.

Application US20080265348 was filed by Philips in May 2005, right before the image sensor group was acquired by DALSA. It contains quite a detailed description of manufacturing steps of backside illuminated imager. It appears that Philips experimented with CMOS BSI well before the acquisition.

Friday, November 14, 2008

At the time when everybody worries about tomorrows markets, Kingpack makes a brave move and expands its image sensor packaging capacity. Digitimes reports that Kingpak Technology, a member of the Kingmax Group, has set a goal to expand its monthly capacity for image sensor packaging and testing from 2-3 million units to 4 million mark.

Sales from the CIS packaging segment account for 60-70% of Kingpak's total revenues at present, said the company. For CIS applications, Kingpak's customers include Micron, Logitech, Chicony, KYE and Quanta, Digitimes sources indicated.

The Toshibe VGA sensor ‘Through Silicon Vias’ TSV reverse engineering report, jointly published by Chipworks and Yole Developpement, analyzes the technology and economics behind Toshiba’s latest Image Sensor. The new report features three different chapters presenting a technical analysis by Chipworks and a reverse costing analysis and the TSV market perspectives by Yole.

Thursday, November 13, 2008

Akihabara News, Electronista report that Sony announced 12, 8 and 5MP sensors and camera modules featuring the new 1.4um pixels. As far as I was able to understand the original Sony Japan announcement, translated by Google, 1/2.5-inch IMX060PQ 12.25MP and 1/4-inch IMX045PQ 5.15MP sensors start sampling in March 2009, while 1/3.2-inch IMX046PQ 8.11MP samples are available in November 2008, that is now. IU060F 12.25MP camera module sampling begins in September 2009, while IU046F 8.11MP module sampling starts in February 2009. The modules have piezoelectric AF, F2.8 lens and 28mm and 32mm equivalent focal length for 12MP and 8MP models respectively.

Regarding the technology, Sony only tells about Cu wiring and column-parallel ADCs used in the sensors. 12MP sensor speed is 10fps at full resolution, while 5MP and 8MP ones have 15fps full resolution speed. All sensors have 1080p/30fps and 720p/30fps HD video modes (except 12MP one having only 27fps in 1080p mode and 5MP one having 60fps in 720p mode). The new 1.4um pixel sensitivity is said to be equal to one of 1.75um pixel.

The sensor's interface is 648MHz 2-lane MIPI and sub-LVDS. Supply voltage is a triple combination of 2.7V for analog, 1.2V for digital and 1.8V for interface (1.8V is probably needed to adopt sub-LVDS voltage levels).

Red color reproduction is one of the most difficult problems in small pixel design. Probably because of that Sony put a magnified inset with red color details in its sample picture from its new 12MP sensor (click on picture to enlarge):

Update: It looks like Sony Insider site has quite a complete translation of Sony Japan PR on 1.4um generation. It also has a translated table with sensor parameters:

Yahoo: Kodak Company promoted Terry R. Taber to the position of Chief Technical Officer, effective Jan. 1, 2009. Taber, who joined Kodak in 1980, is currently the Chief Operating Officer of Kodak’s Image Sensor Solutions (ISS) business.

Prior to joining ISS almost two years ago, Taber, a Ph.D. in Organic Chemistry from Caltech, mainly dealt with silver halide side of Kodak business.

Centre Daily Times: The Strategy Analytics Wireless Device Lab service research, "The Camera is Still King: Consumers Willing to Pay for a Quality Camera on Their Mobile Device," shows that a quality camera is the primary mobile phone add-on for which consumers in the U.S. and Western Europe would be willing to pay--and willing to pay the most--compared to other mobile device features.

These findings are based on a survey of over 2800 wireless device owners in the US and Western Europe. "Strategy Analytics research shows that over 60% of all respondents would be willing to pay extra for a quality camera on their mobile device," commented Chris Schreiner, Senior User Experience Analyst at Strategy Analytics. "This desire for imaging features prevails across all age ranges in both regions."

Wednesday, November 12, 2008

Digitimes sources tell that Seti's shipments of VGA image sensors for white-box handsets in China have climbed to 10M units per month. This represents about 50% of Chinese market, according to Digitimes sources. Seti achieved this by setting aggressive ASPs, bringing VGA sensors to below US$1 in June. Such a strategy puts additional pressure on Omnivision to keep its share on the Chinese market.

"the wafer-level packaging, wafer-level optics, and wafer-level camera, the average amount of time to get in production and revenue varies according to the nature of the licensee’s facility, their experience, and the technologies being licensed. If a licensee has an existing facility, it can take up to one and a half to two years after licensing for royalties to start. If the facility needs to be built from scratch, it takes longer, up to an additional six to nine months. For technologies like our smart optics, it can take one to one and a half years from licensing to royalties."

"In wafer-level packaging, during the third quarter, we announced the second licensee of our SHELLCASE MVP technology, AWLP, based in Seoul, Korea."

"Our first SHELLCASE MVP licensee, Nemotek, is scheduled to be sampling customers in the first quarter of 2009."

"Our first example of our technology integration comes through our product launch services, which we announced on September 22nd. These product launch services offer a combination of technology and resources from our Tel Aviv and Charlotte facilities."

Japan-based THine and Taiwan-based Winbond announced that the two companies agreed to transfer Winbond’s ISP Business to THine. The revenue of Winbond's ISP business in fiscal year 2007 was NT$323 million. Its ISPs is intended to wotk with 3MP to 5MP sensors and AF actuators for smart phones or high-end feature phones.

THine’s intends to use ISP in applications for security cameras, automotive camera systems, amusement machines as well as cell phone handsets and mobile gadgets with cameras.

Yahoo: Omnivision's OV9710 is claimed to be the first megapixel CMOS image sensor designed specifically for automotive vision and sensing systems. Megapixel sensors are the next wave in automotive vision systems, enabling the adoption of advanced forward-looking and extreme-wide angle applications. Initial interest in the OV9710 is said to be strong, and it is currently sampling with multiple automotive customers.

Sigma officially reported that it has acquired 100% of the stock of Foveon. Foveon will continue its sensor development operations in San Jose, CA. The acquisition of Foveon will enhance the development of new types of image sensors and create a synergistic effect with Sigma’s camera and lens business by improving the integration between the camera and sensor.

Monday, November 10, 2008

Yahoo: As stated by the recent report published by Global Industry Analysts, the world market for image sensors is expected to average to $11.7 billion by the year 2012. Currently the market is dominated by Asia-Pacific, Japan, and United States collectively accounting for 79.5% share as estimated in the year 2008.

The world CCD image sensors market is projected to witness declining demand, with the market value expected to deteriorate by US$369.9 million between the period 2008 to 2012. Japan and Asia-Pacific are expected to witness the steepest fall in sales during the aforementioned period. Growth in the world market is fashioned by the CMOS image sensors market, which is projected to witness strong double-digit growth rates. Global sales in this market are expected to rise by US$4,297 million between the period 2008 to 2012.

In Europe, France and Germany, together, collar over 54.2% of the image sensors market as estimated in 2008. Increased competition from China and Taiwan is resulting in falling average prices of image sensors. Adroit utilization of fully depreciated fab lines for manufacturing image sensors is enabling Asian players to offer products at competitive prices to OEMs.

Saturday, November 08, 2008

Tech-On: Ericsson AB of Sweden revealed its efforts in LTE mobile standard promotion at a press conference Nov 6, 2008. During the conference, Ericsson mentioned its concept of a future mobile terminal as "a mobile device in 2012." According to the concept, high-function terminals, in the future, will be equipped with a 12- to 20MP camera and support full HD video shooting capability.

Assuming the "2012 mobile device" has 1/3" sensor, this translates to 1.1um (12MP) or 0.8um (20MP) pixel pitch. As for 1.1um pixel, it's probably safe to assume that it will be mass produced sometime in 2012. I'm less sure about 0.8um generation. Probably Ericsson AB is more optimistic than me on the time table of the image sensor industry. One needs a real leapfrog to make 0.8um in 2012.

It came to my attention there is a new 3D imaging startup in Switzerland, called Mesa Imaging. The company was founded in 2006 as a technology spin-out from CSEM (Centre Suisse d'Electronique et de Microtechnique). The imager gets 3D information using time-of-flight distance measurement principle. Infrared light from the camera's internal lighting source is reflected by objects in the scene and travels back to the camera, where its precise time of arrival is measured independently by each of the sensor pixels. A unique CCD/CMOS imager is in the heart of the camera. The sensor has a fast electronic gate and CCD-like storage area to achieve precise time measurements.

With Mesa Imaging arrival, there are 4 start-ups dealing with time-of-flight imaging. The 3 others are 3DV, Canesta and PMD. Also, Panasonic develops a CCD for 3D sensing.

The differences between all these approaches look quite subtle to me. All talk about necessity of background light suppression and all claim to solve this problem. All companies tell they are cheap enough for the mass market. I hope the 3D time of flight market is big enough to accommodate all five of them.

Friday, November 07, 2008

I got this rumor from two independent sources, both telling that Sigma has acquired Foveon more than three weeks ago. Right before the acquisition Foveon has laid off about a half of its staff, including VPs and CFO. Apparently, the layoff was associated with the closure of mobile image sensor project - the flagship Foveon project in the recent years.

The mobile sensor had 2.2um pixel size with 3-layered photodiodes. Its resolution was supposed to be close to 1.4um pixel, given same physical size of the sensor array. However, Foveon image processing was too heavy for the current mobile phone processors.

Foveon's foundry Dongbu used to provide excellent support, in hopes that Foveon would be successful on the huge mobile sensor market. Now, with no cellular project, the support might be downgraded, which complicates the new sensors development.

All the above are unconfirmed rumors. Like any rumors, you should take these with a grain of salt.

Mobile Handset Design Line publishes a third part of "Image capture and processing challenges and solutions in portable designs". What I thought was the part 3 before is probably not a part of the series.

In the new part Tessera talks about how great is software enhanced optics and the new possibilties it opens, including full optical zoom with no moving parts, extended field depths, and small F-number optics for low-light environments.

Monday, November 03, 2008

Yahoo: Cypress announced sampling of a 3MP 8um pixel image sensor with industry-leading digital data throughput of 13.2 Gbps. The new 3MP LUPA-3000 sensor offers a triggered and pipelined synchronous shutter with a frame rate of 485fps. The pipelined synchronous snapshot shutter allows reading one image while the next is being acquired. The sensor has 32 8-bit digital LVDS outputs, each runs at a 206 MHz pixel rate.

Cypress also announced LUPA-1300-2-color 1.3MP sensor with 14um pixel size, pipelined synchronous shutter and 12 10-bit digital LVDS outputs having a programmable offset and gain amplifier for each channel of the LVDS outputs. Each channel runs at a 61MHz pixel rate, which results in 500fps frame rate at full resolution.

Prototype samples of the LUPA-3000 and LUPA-1300-2-color sensors are available now with production devices expected in the first quarter of 2009.

Saturday, November 01, 2008

Ad Hoc News: Scalado has signed a contract with Samsung to license and integrate Scalado SpeedTags technology into Samsung future mobile multi-megapixel SOC designs featuring 3MP and above. With Aptina and Omnivision announced similar agreements some time ago Scalado SpeedTags get quite a broad support.

Friday, October 31, 2008

So when do you think that significant sales of these CMOS sensors could -- I thought the original target was the second half of next year. Are we able to stick with that target as to when the CMOS sensors start to become a revenue and earnings contributor? Or must we--

Antonio Perez, CEO:

That is the target that we put for ourselves for a significant increase in volume. And that still is the target, Joan.

Joan Lappin - Gramercy Capital:

Okay. So you haven't had to -- no alterations in that.

Antonio Perez:

No.

---

To me this sounds like Joan is a bit skeptical about Kodak being able to achieve its sales target.

Thursday, October 30, 2008

Yahoo: Pixelplus revenue for the Q3 of 2008 was $3.7M, compared to $3.1M in Q2 2008, and $3.9M in Q3 2007. Net loss in Q3 2008 was $2.9M, compared to a net loss of $2.3M in Q2 2008, and a net loss of $1.2M in Q3 2007. Gross margin for Q3 2008 was 15.3%, compared to 4.9% in Q2 2008.

The company sold approximately 7.4M image sensors in Q3 2008, which represents an increase of about 0.3M units from its sale of around 7.1M units in Q2 2008.

Pixelplus CEO and President S.K. Lee says: "The economic slowdown in China had a negative impact on our business in the third quarter, and this impact was much greater and broader than we had ever imagined. In response to the unprecedented financial turmoil arising from the Global Financial Crisis and the severe economic burden this has placed on the Asian economies, we continue to adapt to unfavorable market conditions."

Tech-On: Sony announced its financial results for Q2 (July to September) of FY2008. Its operating income plunged 90.1% on year over year basis. Image sensors were cited as one of the fields where income declined more than the average.

Wednesday, October 29, 2008

Semiconductor International: ST talks about its method for optical inline monitoring of colorization effects on CMOS image sensors in its fab.

Typical defects in the manufacturing process are streaks on the color filter array. They occur after liquid processes, mainly after resist spin-coating steps. A new, automatic and fast optical inspection method for colorization effects was developed by Vistec Semiconductor Systems in collaboration with ST. The successful detection of colorization problems became possible by using an automated macro defect inspection system (Vistec LDS3200) with a combined microscope module and special optimized analysis software. The tool scans a wafer in less than 6 minutes and delivers the inspection result for the full wafer.

Micron just published its FY2008 10-K form. Micron confirms that Aptina already operates as a separate entity: "We are exploring partnering arrangements with outside parties regarding the separation of our Aptina Imaging business to an independent entity in which we would retain a significant minority ownership interest. To that end, we began operating our Imaging business as a separate, wholly-owned, subsidiary in October 2008."

EETimes comes with a post-mortem article on Magnachip exiting image sensor business. Nothing new is there, just re-iteration that the company is in a difficult cash position and it has no choice but to make the hard decisions.

Digitimes also repeats the same info. These reports are mostly based on Magnachip announcement of its Q3'08 results (Yahoo).

Tech-On: Panasonic has developed a 3D range sensor that uses a CCD and can be used at 100,000lux illumination. The range sensor irradiates a signal light on the measurement target and observes the reflected light. In extremely bright ambient light such as direct sunlight, the CCD sensor is saturated with only the ambient light, making it almost impossible to detect the signal light.

In the new sensor, the electric charge corresponding to that generated by the ambient light is removed from the charge generated in the photosensitive unit so that only the charge generated by the reflected light remains. I assume it uses some sort of fast gating to minimize the stray ambient light influence. The 3D CCD resolution is 16x120.

Digitimes: Varioptic is to close its Taiwan branch office, because its "liquid lens solutions are not competitive with conventional VCM (voice coil motor) auto-focus devices in terms of price, according to the branch office."

Yahoo: SMIC announces 0.11um CIS technology. The new process is available with both aluminum and copper metalization, which can be manufactured on 200mm and 300mm wafers - looks like too many options to me. SMIC says it has begun 0.11um pilot production for its customers.

Wednesday, October 22, 2008

Dpreview Forum: Dick Merrill (1949-2008) brought to the table many of the ideas behind the Foveon X3 imager, which he co-invented with Dick Lyon, who was able to see a concept among many of Dick Merrill's patents. Together with Dick Lyon and Carver Mead, Dick Merrill was one of the founders of Foveon. In 2005, these three were awarded the Progress Medal for this work by the Royal Photographic Society of Great Britain.

Dick was a warm and wonderful person and someone who took great pleasure in his passion and the photographic images it provided. In many ways, he was the spirit within Foveon and, before that, Nat Semi.

Monday, October 20, 2008

Yahoo: Sensata got into image sensors a year and a half ago when it acquired the remains of SmalCamera from Cypress. Today Sensata announced the new Avocet HDR technology based on SmalCamera's Autobrite and now offering a dynamic range up to 154dB.

In SmalCamera's tradition to offer a complete system solution, the new technology is presented in three product configurations: a single box complete solution, Vision Systems Platform (VSP); a standard video camera for 2 box solutions; or as an imaging module for engineers building their own camera. All solution are available with monochrome, RGB or RGBi sensor versions.

Yahoo: ST Micro announces its first automotive HDR sensor targeted for driver assistance systems. This new VL5510 sensor has a 1024x512-pixel format, suitable for wide-angle products. Its specifications include: 5.6um pixel size; sensitivity 7.14V/lux, low dark current of 33aA/pixel at 25C, and high QE at near infra-red, frame rate up to 34fps; video delivered via 12-bit parallel interface or serial interface (RAW 8/10/12 format). Anti dark sun and defect pixel correction algorithms are also integrated, together with an image histogram is embedded in the delivered image. The high dynamic response of the sensor is fully programmable: 10 knee points are available to tune pixel response.

The device is currently sampling and will be in mass production in automotive applications in early 2009. Pricing is expected to be in the range of $20 for bare-die quantities of 10,000 pieces.

Philip Garrou from Semiconductor International anticipates a surge of activity in TSV and 3D integration in image sensors. He summarizes TSV activities by all the leading image sensor makers in his nice blog message from a month ago. A newer post paints a bigger picture where image sensor TSV adoption is just a first step of large scale TSV move.

Yahoo: Japan-based Graphin announced image sensor evaluation suite with MIPI interface. Graphin has completed an evaluation for a D-PHY physical layer compliant with the MIPI standard and created a prototyping system with intellectual properties supporting CSI-2 protocol controls. Graphin is working on the MIPI Advanced Board commercially available in December 2008.

Thursday, October 16, 2008

Entertainment technology innovators will be honored by the Society of Motion Picture & Television Engineers during an awards presentation at the organization's annual Tech Conference & Expo, Oct. 28-30 at the Renaissance Hotel in Hollywood.

"The Fuji Gold Medal for the design and development of techniques and equipment advancing photographic or electronic image origination will be bestowed on Dr. Albert Theuwissen, professor at Delft University of Technology and founder of Harvest Imaging, for his contributions to R&D and education in the field of solid-state image sensing."

Digitimes reports that Omnivision is in talks with TSMC and PSC to secure wafer capacity in 2009 to help it further expand market share, according to the paper's sources in Taiwan's wafer foundry industry.

Digitimes says that Omnivision is the top vendor of image sensors in the notebook and handset segments. OmniVision is not being complacent and the company has been trying to grab as much as the global market share through capacity support from foundry companies in addition to continuing product innovation, the sources indicated.

Digitimes sources think that Aptina in its push to expand its capacity is likely to approach TSMC and PSC, as they are the two Taiwan-based foundry services companies that have more production capacity and manufacturing expertise in the production of CMOS image sensors. OmniVision aims to stymie Aptina's efforts to build up business relations with TSMC or PSC through its strengthened cooperation with the two companies, speculated the sources.

Tuesday, October 14, 2008

Mobile Imaging Design Line publishes part three of Tessera's 4-part esse on mobile imaging (parts 1 and 2). Naturally, Wafer Level Package and Wafer Level Camera are named as the important parts of the cost reduction.

Sunday, October 12, 2008

SiOnyx is set up to commercialize the new material discovered by Harward University physicist Eric Mazur. As I understand from the company site "Black Silicon" is a modified material having a narrower than bulk Si bandgap and still compatible with Si process (not necessarily CMOS process). The narrower bandgap allows for higher absorption coefficient for visible light.

It looks like the photodetector is based on photoconductive principle, rather than photodiode, so an additional gain is possible right in the detector itself. The noise would be higher as well, both at low and strong light, but the company does not talk about this so far.

SiOnyx sees a lot of applications for the new photodetector, imaging is one of them. A white paper specifically talks about smaller than 1um pixels, leveraging higher absorption coefficient of Black Silicon.